1. Field
Apparatuses consistent with exemplary embodiments relate to scanning lens apparatuses adopting bimorph actuators.
2. Description of the Related Art
Techniques for precisely scanning images of skin surfaces and tissues under the skin of the human body are in increasing demand in the medical imaging field. In particular, since most cancers occur under epithelial cells and then spread into dermal cells where blood vessels are present, early detection of cancers through biopsy of the epithelial cells is important. The internal tomography may be acquired through the skin by using a conventional magnetic resonance imaging (MRI) technique, a computerized tomography (CT) imaging technique, or an ultrasonic imaging technique. However, early detection of cancer, which is small in size is difficult due to the low resolution of a tomogram obtained by the conventional imaging techniques.
However, a recent optical coherence tomography (OCT) technique is capable of detecting cancer with a size of 50˜100 μm earlier. This is because the OCT technique has a resolution approximately ten times greater than that of the ultrasonic imaging technique even though its penetration into the skin is as low as 2˜3 mm. However, because the OCT technique has a lower resolution level than that of a microscope, the OCT technique cannot replace a biopsy and histology used for differentiating an actual cancer. For early differentiation of a cancer, an area scanning apparatus such as a lateral scanning apparatus, besides a depth scanning apparatus, is needed.
A confocal microscopy allows a cancer diagnosis of an internal tissue through a high resolution surface imaging method without performing a biopsy. However, the confocal microscopy requires a high numerical aperture (NA) optical system for high resolution in a horizontal direction and actuators for lateral scanning and area scanning.
A conventional actuator includes a pneumatic actuator, a rotating prism, a galvano mirror, and an electrostatic micro-electrical-mechanical-system (MEMS) scanner. However, miniaturization and increasing the speed of these devices are difficult.
An actuator that uses a bimorph can move an end of a member on which a bimorph is mounted to a side by applying a voltage. However, the end of the member cannot move in a horizontal direction but moves at a slant with respect to an object. Therefore, a correct image cannot be rapidly scanned.